New research backs up past findings that individuals who work rotating night shifts have an increased risk of cardiovascular disease (CVD) and cancer as well as mortality from these conditions.
The effects are believed to be related to disruptions in the natural circadian rhythm, which plays an important role in cardiovascular health and antitumor activity, Elsevier Health Sciences reported.
The recent findings show women who worked rotating night shifts for five or more years had a modest increase in all-cause and (CVD) mortality, and those who worked on this schedule for 15 years also had an increased risk of lung cancer mortality.
To make their findings, the researchers looked at CVD and cancer mortality in a study including almost 75,000 registered U.S. nurses. The findings suggest mortality from all causes is 11 percent higher in women with between six and 14 years of rotating shift work and CVD mortality is between 19 and 23 percent higher in this group as well. There did not appear to be an association between shift work and cancer mortality except in the case of lung cancer, in which risk increased by 25 percent after 15 years of this type of schedule.
The recent study is "one of the largest prospective cohort studies worldwide with a high proportion of rotating night shift workers and long follow-up time," said Eva S. Schernhammer, Associate Professor of Medicine, Harvard Medical School, and Associate Epidemiologist, Department of Medicine, Brigham and Women's Hospital.
"These results add to prior evidence of a potentially detrimental relation of rotating night shift work and health and longevity...To derive practical implications for shift workers and their health, the role of duration and intensity of rotating night shift work and the interplay of shift schedules with individual traits (e.g., chronotype) warrant further exploration," Schernhammer concluded.
The findings were published in a recent edition of the American Journal of Preventive Medicine.
